Rechargeable (i.e., secondary) batteries that include positive electrode (i.e., cathode) active materials based on nickel (Ni), manganese (Mn), and cobalt (Co) oxides (herein “NMC”s) have yet to demonstrate energy densities equal to the theoretical energy densities calculated for these materials and the electrochemical cells in which these materials are used as the positive electrode active material. For example, a theoretical energy density of 1065 Wh/kg is predicted for certain known NMCs, but the best commercially available NMC has an energy density of only 702 Wh/kg. Much work is therefore still needed to increase the empirical energy density of NMCs, to match the NMC energy density to the calculated energy density for these materials, as well as to increase the power output of NMCs when used as positive electrode active materials in secondary batteries (e.g., Lithium rechargeable batteries).
Some researchers have manipulated the amounts of cobalt (Co), manganese (Mn), and nickel (Ni) in NMCs, and/or have doped NMCs with iron (Fe), aluminum (Al), magnesium (Mg), and nickel (Ni), in order to attempt to produce NMCs having improved energy densities, power capabilities, and safer positive electrode materials (See, e.g., U.S. Patent Application Publication No. 2014/0197357, to Ofer et al.; also U.S. Pat. No. 6,677,082, also 6,680,143; also U.S. Pat. No. 8,213,154, to Sullivan, et al.; also U.S. Pat. No. 7,381,496, to Onnerud, et al.; also Ates, et al., Journal of the Electrochemical Society, 161 (3) A355-A363 (2014); also W. El Mofid, et al.; Journal of Power Sources, 268 (2014) 414-422; also Journal of the Electrochemical Society, 147 (5) 1722-1729 (2000); also H.-B. Kim, et al. Journal of Power Sources 179 (2008) 347-350, J Electrochem Soc 147 (10) 3598-3605 (2000)). However, the materials set forth in these reports do not demonstrate the thermodynamically predicted energy densities for NMCs. Also, these reports show that if the amount of nickel is increased beyond a Ni:Mn:Co ratio of 5:3:2, the NMC material is not thought to be stable when electrochemically cycled. As more Ni is inserted in the crystalline lattice, the energy associated with evenly and uniformly distributing the transition metals within a given unit cell (e.g., wherein each metal has a nearest neighbor of another kind of metal) increases. After some initial electrochemical cycling, currently known NMC materials suffer from voltage fade as well as other detrimental effects. In some other reports, a discharge model suggests that when 66% (Li1.08NMC or greater) of lithium enters the NMC, the capacity of the material decreases to 180 mAh/g. However, these same materials are expected to have a yet unrealized theoretical capacity of 272 mAh/g. As such, there is a need for new NMCs, including stable NMC which have high nickel content, as well as methods of making these NMCs.
The disclosure herein sets forth novel oxide materials, and also methods of making and using oxide materials which include nickel, manganese and cobalt, which overcome the aforementioned challenges and limitations as well as other challenges which are known in the relevant field to which the instant disclosure pertains.